Trolling motors are generally suspended beneath the surface of water on a mounting structure affixed to the bow or stern of the boat. When trolling, it is not uncommon that a submerged object will be struck by the motor, causing extensive damage to the motor and mounting structure. In the past, various shock-absorption methods have been used to lessen and absorb the energy created by engagement of the motor with the obstacle.
U.S. Pat. No. 3,240,453 illustrates a shock-absorption system adapted for stern-mounted outboard drive motors. The motor is secured to the transom of the boat by swivel, tilt, and clamp brackets on a swivel pin. When the motor strikes an underwater object, the swivel bracket freely tilts out of the path of the object in an upward direction. The gear sector on the swivel bracket engages with the pinion attached to the clamp bracket that is affixed to the boat. Gear sector teeth are adapted to intermesh with corresponding teeth on the pinion, which actuates the clutch. Springs engage the clutch plate and clutch rings to absorb the kinetic energy. Tilting continues forward until the object is cleared, then motion is reversed until the gear segment engages the pinion and clutch system to freefall back to the motor's normal downward operating position. This is a complicated structure and it is exposed so that the gear assembly can jam. Protection is only afforded in one direction.
U.S. Pat. No. 4,734,068 demonstrates a mounting bracket system secured to the bow-mount supporting assembly. When the trolling motor strikes an underwater object, the force created will overcome the force typically maintained by compression springs on thrust pads and pins. The motor support bracket will pivot until the thrust pins reach the ends of the curved arcuate elongated slots on the cam surfaces. Upon release of the force on the compression springs, the thrust pins return to their normal operating position maintained by the compression springs. This design has several shortcomings. It is expensive to make curved slots. The metal-to-metal contact of the moving parts cain, over time and with exposure to saltwater or other corrosive environments, gall and make future movement less likely or impossible. The metal-to-metal contact also can result in paint scraping off, making for an unsightly appearance or promoting rust.
Accordingly, one of the objects of the present invention is to eliminate damage to trolling motors by providing an efficient shock-absorption system that entails easy assembly and carefree maintenance.